What are Pathogens?
- Pathogens are microscopic organisms that cause or have the potential to cause disease.
- Different types of pathogens include bacteria, viruses, protists (amoeba, plasmodium, etc.), fungi, parasitic worms (flatworms and roundworms), and prions. While these pathogens cause a variety of illness ranging from minor to life-threatening, it is important to note that not all microbes are pathogenic.
- In fact, the human body contains thousands of species of bacteria, fungi, and protozoa that are part of its normal flora. These microbes are beneficial and important for proper operation of biological activities such as digestion and immune system function.
- They only cause problems when they colonize locations in the body that are typically kept germ-free or when the immune system is compromised. In contrast, truly pathogenic organisms have a single goal: survive and multiply at all cost.
- Pathogens are specially adapted to infect a host, bypass the host’s immune responses, reproduce within the host, and escape its host for transmission to another host.
How Pathogens Are Transmitted?
Pathogens can be transmitted either directly or indirectly. Direct transmission involves the spread of pathogens by direct body to body contact. Direct transmission can occur from mother to child as exemplified with HIV, Zika, and syphilis. This type of direct transmission (mother-to-child) is also known as vertical transmission. Other types of direct contact through which pathogens can be spread include touching (MRSA), kissing (herpes simplex virus), and sexual contact (human papillomavirus – HPV). Pathogens can also be spread by indirect transmission, which involves contact with a surface or substance that is contaminated with pathogens. It also includes contact and transmission through an animal or an insect vector. Types of indirect transmission include:
- Airborne – pathogen is expelled (typically by sneezing, coughing, laughing, etc.), remains suspended in air, and is inhaled by or comes in contact with respiratory membranes of another person.
- Droplets – pathogens contained in droplets of body fluid (saliva, blood, etc.) contact another person or contaminate a surface. Saliva droplets are most commonly spread through sneezing or coughing.
- Foodborne – transmission occurs through eating contaminated food or by improper cleaning habits after handling contaminated food.
- Waterborne – pathogen is spread by consumption or contact with contaminated water.
- Zootonic – pathogen is spread from animals to humans. This includes insect vectors that transmit disease through biting or feeding and transmission from wild animals or pets to humans.
While there is no way to completely prevent pathogen transmission, the best way to minimize the chances of acquiring a pathogenic disease is by maintaining good hygiene. This includes washing your hands properly after using the restroom, handling raw foods, handling pets or pet excrement, and when coming in contact with surfaces that have been exposed to germs.